Locating research on a commercial farm is essential for three types of investigation: studies involving 1) management histories and physical conditions not available on experiment stations; 2) farmer management, especially of innovative systems; and 3) ecological effects of whole-farm changes. On-farm research with the farmer involved beyond assisting with operations has advantages in the design, implementation, and dissemination stages. These benefits may warrant locating a project on a commercial farm even if it could also be done on-station. Misunderstandings about the value of on-farm research are often due to its promotion in conjunction with sustainable agriculture and greater political power for farmers. On-farm research, especially with high farmer involvement, is more appropriate for answering some questions critical to developing more sustainable agricultural systems; but other aspects of sustainable agriculture are more suitably studied at experiment station sites. Greater involvement of farmers in all stages of a project is conducive to improving communication and cooperation with agricultural researchers and administrators. However, not all research on farms should have this kind of farmer involvement; and simply increasing the amount of on-farm research does not necessarily augment farmers' political power.